Most adults sleep about six to eight hours a day, or spend approximately a quarter to a third of each day sleeping. Therefore, the enhancement or improvement of sleeping quality is highly desired. Long-term research results show that many people suffer from sleep disorders, some notable examples of which are insomnia, snoring, sleep apnea, somnambulism, and somniloquy. According to related studies, the probable causes of sleep disorders include stress, a fast pace of life; pain, tobacco, caffeine, alcohol, medication, and so on.
Of all the aforementioned sleep disorders, snoring and sleep apnea draw the most attention from the general public and the medical community. Snoring, which is common among overweight male adults, results from vibration of the edge of the soft palate, and of the secretion of its mucous membrane, when air flows through the upper respiratory tract of someone sleeping. Overweight people are more likely to snore because they tend to have a reduced pharyngeal cavity due to the fat gathering around the throat. Snoring is often accompanied by other symptoms such as drowsiness during the day and headache in the morning. Sleep apnea, on the other hand, refers to shallow or difficult respiration while sleeping and is caused by repeated collapse of the upper respiratory tract (including the nasopharynx, oropharynx, and laryngopharynx) that obstructs the passageway. In severe cases of sleep apnea, complete blockage of the passageway may prevent respiration or even lead to suffocation. While a narrow respiratory tract is attributable to obesity, insufficient muscle strength to maintain free flow in the respiratory tract is also one of the major causes of sleep apnea. In addition, a retruded chin, enlarged tonsils, and an oversized uvula may narrow down the respiratory tract and are responsible for some sleep apnea cases. By medical definition, respiration disorders during sleep can be divided into apnea, which is characterized by pauses of oral and nasal airflow for more than ten seconds, and hypopnea, which is characterized by an at least 50% reduction in pulmonary ventilation volume that lasts for more than ten seconds. The apnea-hypopnea Index (AHI) is composed of the average number of apnea events and the average number of hypopnea events in one hour. Normally, an adult is clinically diagnosed with sleep apnea when his or her AHI has an apnea component greater than five.
It is known from the above that both snoring and sleep apnea are closely related to the breathing condition. Snoring is also generally regarded as a primary symptom of sleep apnea. It is therefore a common goal for the related industry and the medical community to find a way to effectively detect whether someone is snoring and stop the snoring in a timely manner. So far, a snoring sound detector has been successfully developed in Japan. The snoring sound detector has an audio sensor for receiving the user's snoring sound and analyzing the audio signals received, and the user is determined as snoring or otherwise according to the intensity and frequency of the snoring sound. When the snoring sound detector is used, the audio sensor must not be too far away from the user, or the audio sensor will pick up undesirable background noise. Because of that, the user is required to wear the audio sensor around the head, or more specifically on the face, so that the audio sensor is close to the user's nose. However, wearing the audio sensor not only is inconvenient to the user, but also makes the user feel restrained during sleep, which lowers sleeping quality.
Besides, an airflow-based snore detector has been developed in the United States, as shown in FIG. 1. An airflow meter 10 of this snore detector continuously measures the flow of the user's respiration and estimates the user's breathing condition accordingly, thereby determining whether the user is snoring or not. In order to precisely measure the airflow through the user's nostrils, the airflow meter 10 must be secured around the nostrils when the snore detector is used. Additionally, a sensor 11 has to be attached to the user's chest for counting the number of times the user breathes in a predetermined time unit. In other words, snore detection cannot be done without the user wearing the aforesaid devices, which, however, are a source of discomfort and may seriously compromise sleep quality—especially that of those who are more sensitive, if not inviting other sleep disorders.
Aside from the foregoing snore detectors, attempts have been made to apply medical instruments to snore detection. For example, it has been contemplated to detect snoring by means of an electroencephalography (EEG) or electrocardiogram (ECG) monitor. Nonetheless, such professional medical instruments are costly and not suitable for domestic use. Further, in order for the medical instruments to obtain the user's physiological parameters such as heartbeat and respiration rates, electrodes must be attached to the user's body during detection, and yet long-term attachment of the electrodes to the skin may cause skin irritation or even skin lesions. Therefore, the idea of using the aforesaid medical instruments to detect snoring is cost inefficient, potentially harmful to the user's skin, and impractical. Moreover, all the detection devices mentioned above can only detect snoring but cannot stop the users from snoring, which leaves much to be desired.
Hence, the issue to be addressed by the present invention is to overcome the various drawbacks of the conventional snore detectors and design a novel snore detection system which performs non-contact detection to avoid the use of electrodes or audio sensors, and which, upon detecting that the user is snoring, can timely adjust the configuration of a bed so as to effectively stop the user from snoring.